The Senate has unanimously declared John McCain a natural-born citizen, eligible to be president of the United States.

That is the good news for the presumptive Republican nominee, who was born nearly 72 years ago in a military hospital in the Panama Canal Zone, then under U.S. jurisdiction. The bad news is that the nonbinding Senate resolution passed Wednesday night is simply an opinion that has little bearing on an arcane constitutional debate that has preoccupied legal scholars for many weeks.

Article II of the Constitution states that "no person except a natural born citizen . . . shall be eligible to the office of president." The problem is that the Founding Fathers never defined exactly what they meant by "natural born citizen," and the matter has never been fully tested in court. At least three pending cases are challenging McCain's right to be sworn in as president.

Jurists on both sides of the political divide, consulted by the McCain campaign, insist that the issue is clear-cut. They argue that McCain is a natural-born citizen because the United States held sovereignty over the Panama Canal Zone at the time of his birth, on Aug. 29, 1936; because he was born on a U.S. military base; and because his parents were U.S. citizens.

But Sarah H. Duggin, an associate law professor at Catholic University who has studied the "natural born" issue in detail, said the question is "not so simple." While she said McCain would probably prevail in a determined legal challenge to his eligibility to be president, she added that the matter can be fully resolved only by a constitutional amendment or a Supreme Court decision.

"The Constitution is ambiguous," Duggin said. "The McCain side has some really good arguments, but ultimately there has never been any real resolution of this issue. Congress cannot legislatively change the meaning of the Constitution."

Senators sympathetic to McCain's position, including Democrats Claire McCaskill (Mo.) and Patrick J. Leahy (Vt.), dropped an earlier attempt to quell the eligibility controversy with legislation. McCaskill acknowledged in an interview that there is "no way" to completely resolve the question short of a constitutional amendment, a cumbersome process which could not be concluded before November.

She described the nonbinding resolution, which she sponsored, as "the quickest, clearest and most efficient" way for the Senate to send a message to the courts that McCain has the right to be president.

One person who disagrees with that premise is New Hampshire resident Fred Hollander, who has filed a suit in U.S. District Court claiming that the Republican candidate is "not a natural born citizen." In an attempt to prove his argument, the 49-year-old computer programmer filed a subpoena last month seeking McCain's birth certificate.

The Department of Homeland Security, which oversees citizenship services, declined to hand over copies of the document, saying the subpoena was improperly served.

In his autobiography, "Faith of My Fathers," McCain writes that he was born "in the Canal Zone" at the U.S. Naval Air Station in Coco Solo, which was under the command of his grandfather, John S. McCain Sr. The senator's father, John S. McCain Jr., was an executive officer on a submarine, also based in Coco Solo. His mother, Roberta McCain, now 96, has vivid memories of lying in bed listening to raucous celebrations of her son's birth from the nearby officers' club.

The birth was announced two days later in the English-language Panamanian American newspaper. A senior official of the McCain campaign showed a reporter a copy of the senator's birth certificate issued by Canal Zone health authorities, recording his birth in the Coco Solo "family hospital."